Compilation error with custom Allegro 4 include dir

[msikma]

Hi there. I'm trying to compile this project on OSX (10.12.6), but I've got a bit of a weird setup. Allegro 4 cannot easily be compiled anymore on modern OSX, so I compiled a version using the OSX 10.4 SDK that will run on modern versions. (Last time I tried, the brew allegro4 install script was broken.)

Since I'm using this build of Allegro 4, I need to ensure that it can find the library and include files, which I currently do by configuring with: cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr/local -DBUILD_SHARED_LIBS:BOOL=ON -DBUILD_ALLEGRO4:BOOL=ON -DALLEGRO_INCLUDE_DIR="/Users/msikma/liballeg.4.4.2-osx/include/" -DALLEGRO_LIBRARY="/Users/msikma/liballeg.4.4.2-osx/lib/liballeg.4.4.2.dylib" ..

However, as soon as the compilation reaches Allegro, it errors out:

/Users/msikma/Source/dumb/src/allegro/alplay.c:22:10: fatal error: 'allegro.h' file not found

If I run make -n to find the command it's trying to run, and manually add -I/Users/msikma/liballeg.4.4.2-osx/include to it, the compilation succeeds.

Is there any way I could add the passed ALLEGRO_INCLUDE_DIR to the compilation commands during generation? I'm not really very familiar with Cmake so any help would be appreciated...

[Rondom]

This is a bug in our CMakeLists.txt. I will go about submitting a PR tomorrow.

[msikma]

Is it a matter of adding include_directories(${ALLEGRO_INCLUDE_DIR}) to the BUILD_ALLEGRO4 statement? That seems to work.

[msikma]

Oh, I just realized also that the following line in cmake-scripts/FindAllegro4.cmake might be problematic:

exec_program(allegro-config ARGS --libs OUTPUT_VARIABLE ALLEGRO_LIBRARY)

If I'm linking to an Allegro library somewhere else, allegro-config won't work and the configuration will have an invalid value in it:

...
-- Found Allegro: /bin/sh: allegro-config: command not found
...

Didn't mention this before since I modified this file to get it to work and forgot about it.

[Rondom]

The first issue with the include path is fixed by cab1803.

Regarding the second issue, is there a standard environment variable that is used in other build systems to specify the path to the allegro-config binary?

Adding the directory to your path during the invocation of cmake should also help, without you needing to modify any files.

[SimonN]

I don't think Allegro 4 had a standard variable for its binaries. They're generally expected to be in the path, thereore I would add your local A4 directory to your path variable.

[msikma]

I'm not sure if it's necessary to have allegro-config. As far as I can tell, just setting the $ALLEGRO_LIBRARY manually is sufficient, so it's possible to just check if that variable is set and if not to run allegro-config. This makes it possible to link to Allegro 4 without having to actually have it installed and in the path.

In my case this is useful because I'm actually cross-compiling, so I'm not actually installing A4, but just linking to it.

[SimonN]

check if that variable is set and if not to run allegro-config

This is a good idea.